Polycarboxylic acids



Patented Apr. 13, 1943 UNITED STATE POLYCARBOXYLIC ACIDS Donald J. Loder and William F. Gresham, Wilmington, Del., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application July 13, 1940, Serial No. 345,420

1 Claim.

This invention relates to a process for the preparation of polycarboxylic acids and more specifically to the preparation of amino polycarboxylic acids and acetals. v

The compounds are obtained by the interaction of one mole of an amino acetal, in an alkaline solution with from 4 to 5 moles of a mono halogenated carboxylic acid (or the amino acetal with an alkali metal salt of the acid.) at temperatures between 20 and 100 C. and under normal pressures, although pressures above or below atmospheric may be used if desired. The amino polycarboxylic acids are thus obtained as salts in solution; ifit is desired, the free acid can be liberated by acidification of the solution of the salt.

Examples of amino acetals which maybe reacted in accord with the process of this invention are ethanol amine formal,

CH2 (OCHnCHzNI-Iz) 2 propanol amine formal, CH2(O (CI-I):;NH2)2; and the higher straight and branched chain symmetrical formals as well as the unsymmetrical formals such as ethanol propanol amine formal,

their salts from the amino 0 CHiCHrOH owHmNm methanol amine, ethanol amine formal,

o o H=Nm 0 C HrCHzNHi ethanol amine propanol amine formal,

cmcmNng cmcmcmNHa and the like. The process is applicable not only to the preparation of polycarboxylic acids and their metal salts from these formals but likewise to their preparation from the similar higher acetals such as the acetals, propanals, and higher similar derivatives such as are designated by the empirical formula:

in which the R groups designate hydrogen and/or hydrocarbon groups; n is an integer, Q is oxygen or nitrogen, and when Q is oxygen QHRH becomes 0H.

These acetals may be reacted with the halogenated carboxylic acids generally, but more particularly the mono a halogenated fatty acids such as mono chloracetic acid, mono or chlorpropionic acid, mono or chlorbutyric acid, and the like.

By this process amino polycarboxylic acids having the following empirical formula are obin which the R groups are hydrogen and/or hydrocarbon groups; n is an integer, a: is 0 or 1, Z is the radical (in which R9 and R10 are hydrogen and/or hydrocarbon groups, and y is an integer), Q is oxygen or nitrogen, and when Q is oxygen (R'l)a: drops out and 22% becomes Z. Thus from ethanol amine formal is produced CHzlOCEIzCHzMCHsCOOH) 212 from propanol amine formal,

CH2[O(CH'2)3N[CH2COOH]2]2 and from ethanol, ethanol amine formal,

CH2 OCHzCHzN (CHsCOOH) 22 OCHaCHzOCHzCOOI-I The following example will further illustrate the invention without limiting it to the details shown. The parts given are by weight.

Example 1.-Sodium ethanol amine formal N,N,N ,N -tetracetate (NaOOCCHz) zNCHzCHzOCI-llz OCmCH2N CH::COON a) 2 The polycarboxylic acids and especially their water-soluble salts, such as their salts with basic reacting organic compounds, with ammonia,

substituted ammonia, and alkali metals give products which are useful as detergents, deter gent assistants, hard-water softening agents, lime sequestering agents, dye assistants, and water-treating agents generally, for use in deterglng, flocculating, defiocculating, dyeing, and wetting. They are further useful in the wetting out of gray goods, as assistants i peroxide bleaching, as lime dispersing agents, for scouring rayon yarns and; fabrics, for wetting out of cotton goods that are to be pre-shrunk, scouring of lime-pulled wool, degumming, preparation of raw stock for dyeing, as a dispersin and penetrating agent in dyeing, penetrating foaming,

agent in warp sizing, in alkaline fulling, and generally in processes where detergents, detergent assistants, and water-treating agents are used with advantage.

We claim:

A process for preparing sodium ethanol amine formal N tetracetate having the empirical formula which consists in admixing with stirring and cooling below C. a solution of 47.2 parts byweight chloracetic acid in parts by weight water. and a solution of 20 parts by Weight sodium 5 hydroxide in parts by weight water, then i incorporating 1-6.7 parts by weight ethanol amine formal and 31 parts by weight sodium carbonate monohydrate; allowing the reaction mixture to stand at 20 to 35 for four hours, then heating 20 the reaction mixture to to for an additional four hours, cooling and filtering ofi precipitated sodium bicarbonate, and separating a filtrate containing sodium ethanol amine formal N-tetracetate.

25 DONALD J. LODER.

WILLIAM F. GRESHAM. 

